Safety ski binding

ABSTRACT

Fore and heel clamp portions of a ski binding respectively designed to release the tip of the boot and the heel from the ski in response to twisting moments about vertical and horizontal axes are built into recesses in the heel and tip of the boot sole. Each clamp portion has resiliently biased sliding elements which normally clamp the boot to the ski by engaging fastening elements mounted on the ski, the bias being so set that the clamping elements will be released from the fastening elements when the force of the twisting moment exceeds the force of the bias.

United States Patent Ribi [451 Sept. 5, 1972 [54] SAFETY SKI BINDING FOREIGN PATENTS OR APPLICATIONS 2] Inventor: Guido i, v ,I 1y 62,295 1/1927 Sweden ..2s0/11.35 R [73] Assignee: Cober Fabbrica Articoli Sportivi, 134,284 10/1929 Switzerland ..280/l 1.35 D

e a Milan, Ital op r y Primary Examiner-Benjamin Hersh Flled: March 1971 Assistant Examiner-Milton L. Smith 211 App]. No.2 119,719 Kelman [57] ABSTRACT [30] Foreign Application Priority Data Fore and heel clamp portions of a sh binding respec- March 2, 1970 Italy "1251-3 A/70 tively designed to release the tip of the boot d the heel from the ski in response to twisting moments 31.2.8]. liislz about vertical and horizontal axes are built into I recesses in the heel and ip of the boot S0le Each [581 of Seal-$280,113; i 1 3 6 1 clamp portion has resiliently biased sliding elements 280/11 5 which normally clamp the boot to the ski by engaging fastening elements mounted on the ski, the bias being [56] References Clted so set that the clamping elements will be released from UNITED STATES PATENTS the fastening elements when the force of the twisting moment exceeds the force of the bias. 3,061,325 10/1962 Glass ..280/l1.35 D 3,606,368 9/1971 Smolak et al. ..280/l 1.35 D 12 Claims, 10 Drawing Figures sleasloss PATENTEUSH' 5M 45 INVENTOR 60.! D0 R 18 I 74M iaw SAFETY SKI BINDING The present invention relates to a safety ski binding 7 normally holding a ski boot on a ski and automatically releasing the boot from the ski in response to a predetermined twisting moment exceeding in force a clamping bias exerted upon clamping elements in the binding.

It is one object of this invention to provide a safety ski binding whose clamping bias is automatically built into the binding when the boot is clamped to the ski by the binding.

It is another object of the invention to provide a safety ski binding of this type whose over-all dimensions are so small that it may be built into the boot sole and heel and which is so simple that it may be manufactured at a relatively low cost.

The above and other objects are accomplished in accordance with the present invention with a ski binding which comprises a fore clamp portion and a heel clamp portion. The fore clamp position is designed to release the tip of the boot from the ski in response to a twisting moment about a vertical axis for permitting lateral motion between the boot tip and the ski, and the heel clamp portion is designed to release the heel of the boot from the ski in response to a twisting moment about a transverse and horizontal axis for permitting release of the boot heel from the ski. v

The fore clamp portion includes a casing having an open front end and fitted into a conformingly shaped recess in the tip of the boot sole. A sliding block is slidingly guided in the casing for reciprocating motion. Resilient biasing means urges the sliding block forwardly through the open end of the casing, and means is provided for pre-setting the force of the resilient bias of the biasing means. The fore clamp portion effectuates the release when the force of the twisting moment exceeds the pre-set force of the resilient biasing means, and a clamping member is mounted on the ski for clamping engagement with the sliding block when the pre-set force exceeds the twisting moment.

The heel clamp portion includes a casing fitted into a conformingly shaped recess in the heel. A pin is journaled in the heel clamp portion casing at one end thereof for free rotation about a transversely extending horizontal axis. The pin is arranged near the top of the casing and has a substantially diametrical guide bore intermediate it ends. An obliquely inclined rod has one end received in the guide bore for sliding movement therein, the rod extending in a direction perpendicular to the axis of the pin, and an adjustably mounted stop means is preferably mounted on the one rod end for limiting the sliding movement of the rod and thus to prevent the rod from moving out of the guide rod. At least one clamping cam, and preferably a pair of symmetrically arranged cams, is pivotally connected at a base end of the cam to the opposite end of the rod for pivotal movement about a transverse and horizontal fulcrum. The opposite or clamping end of each cam has a recess. A resilient biasing means urges the sliding rod downwardly against the clamping cam base end and out of the guide bore. Means is provided for pre-setting the force of the resilient bias of the sliding rod biasing means, and the heel clamp portion effectuates the release when the force of the twisting moment about the horizontal axis exceeds the pre-set force of the resilient biasing means. A pin is associated with each cam, each pin being mounted on the ski for clamping engagement with the recess of the associated clamping cam when the biasing force exceeds that of the twisting moment.

The above and other objects, advantages and features of the present invention will be more readily understood by reference to the following detailed description of a now preferred embodiment of the'safety ski binding, taken in conjunction with the accompanying drawing wherein:

FIG. 1 is a side elevational view of a ski boot incorporating the safety ski binding, the heel and tip portions of the boot being shown in section to illustrate the mounting of the ski binding therein;

FIG. 2 is an enlarged axial cross section of the heel clamp portion of the ski binding;

FIG. 3 is an exploded perspective view of the casing holding the heel clamp portion;

FIG. 4 is a side elevational view of a fastening device attached to the ski for engaging the heel clamp portion;

FIG. 5 is a perspective view of a heel clamp portion cam designed to cooperate with the fastening device of FIG. 4;

FIG. 6 is a perspective view of the casing holding a fore clamp portion of the ski binding;

FIG. 7 is a top plan view of the fore clamp portion in the casing;

FIG. 8 is a side view, partly in section, of the casin and parts of the fore clamp portion;

FIG. 9 is a perspective view showing a structural detail of the fore clamp portion; and

FIG. 10 is a perspective view of a rotary pin mounted in the ski and designed to cooperate with the fore clamp portion of the binding.

As will become obvious from the following description, the heel clamp portion of the safety ski binding of this invention is designed to ensure the release of the ski boot from the ski when the boot is subjected to a twisting moment about a transverse horizontal axis while the fore clamp portion ensures the release of the boot from the ski in response to a twisting moment about a vertical axis. The magnitudes of the twisting moments causing automatic release may be adjustably pre-set.

Referring now to the drawing and first to FIG. 1, it will be noted that the heel clamp and fore clamp portions are each mounted in casings which may be fitted in conformingly shaped recesses respectively provided in the heel of the ski boot and in the tip portion of the ski boot sole. These casings may be inserted into, and pulled out of, the respective recesses wherein they are housed in a sliding motion, being locked therein, when in use, by any suitable retaining mechanism (not shown).

As will be seen from FIG. 3, the casing l for the heel clamp portion has a bottom 2 which may be rivetted or otherwise attached to a pair of longitudinally extending flanges projecting from the top casing. The bottom defines an inspection window 4 which is closed by a slidable or hinged cover 3 so that the clamping mechanism may be adjusted and pre-set in a manner to be described hereinafter. Furthermore, a closure member 101 is centered between the clamping cams of the mechanism, also to be described hereinbelow, to prevent foreign objects from entering into the casing and interfering with the operation of the mechanism.

The heel clamp mechanism mounted in casing 1 comprises the following parts:

A transversely extending, horizontal pin 5 is rotatably journaled in the top of easing 1 at one end thereof. A substantially diametrical guide bore extends through pin 5 intermediate its ends and slidingly receives a rod 6 extending perpendicularly to the axis of pin 5 and substantially in the direction of ski 33. It is useful to limit the sliding movement of rod 6 by nut 8 mounted on end 9 of the rod. A return spring 10 is attached to the rod end 9 and the casing bottom 2, respectively, to bias the rod end 9 downwardly i.e. clockwise.

A compression spring 1 l is mounted coaxially on rod 6 between a freely movable shoulder 7 and threadedly mounted nut 12, the spring load being adjustably preset by moving nut 12 inwardly or outwardly along the rod. The nut 12 is in alignment with inspection window 4 to enable the nut to be operated by removing the cover 3. Thus, the heel clamp portion will be automatically responsive to any twisting moment about a transverse horizontal axis exceeding the preset load of helical spring 11.

The rod end opposite to end 9 has a head 13 which is pivotally connected to a pair of clamping cams 14 mounted thereon for pivotal movement about transverse and horizontal fulcrum 15, the clamping cams being arranged laterally adjacent respective sides of rod head 13 at the respective side walls of the casing top, the open space between the two clamping cams being covered by closure member 101. The free end of each clamping cam opposite to the fulcrum thereof defines a recess 16 designed for clamping engagement with a transverse and horizontal pin 17 fastened to ski 33 in a manner more fully described hereinafter with reference to FIG. 4.

Under normal operating conditions, i.e. when the ski binding is operative to attach the boot to the ski, the clamping cam recesses 16 and the associated pins 17 are interengaged to hold the boot heel on the ski. When a twisting moment is applied to the ski boot and, therefore, to casing l, which is fixedly held in the ski boot, in the direction of arrow 18 about an axis parallel to fulcrum 15, the boot and easing will be forced to turn in the direction of this arrow. The pins 17, on the other hand, are fixed to ski 33, i.e. they will not move. Being engaged in recess 16 of the clamping cam, each pin will rotate the associated cam in the opposite direction indicated by arrow 19, lifting the rod head 13 and for forcing the rod 16 to pivot upwardly in the direction of arrow 20 relative to casing 1. This pivoting movement of the rod will simultaneously cause the rod to slide through the diametrical guide bore in pivoting pin 5 and thus increase the compression of spring 11, i.e. its load.

When the ski binding is in operative condition i.e. the boot is bound to the ski, compression spring 11 biases the rod head 13 against the base of the pivotal clamping earns 14, which imparts an upward pivoting force to the cams and tends to hold them resiliently in engagement with the pins 17. The boot is thus yieldingly held on the ski, which permits such foreign bodies as pebbles, snow, ice and the like to lodge between the ski and the boot without interfering with the binding action. However, when the force of a twisting moment in the direction of arrow 18 exceeds the pre-set force of spring 11, pins 17 will pivot the clamping cams downwardly in the direction of arrow 19, causing the base of the clamping cams to be lifted and the clamping cam recesses 16 to become disengaged from pins 17,

thus releasing the heel of the boot from the ski.

To re-engage the ski boot heel, it will be sufficient for the skier simply to move the heel forcefully downwardly until the recesses 16 of the clamping cams snap back into engagement with pins 17. As the heel ispressed down, the clamping mechanism 14, 6 will be brought back into the position shown in FIG. 2. This heel clamping motion will be facilitated further if the two flanks 21 and 23 of the clamping cams 14, which respectively engage the top and bottom of the casing l, are differently shaped to ease the movement of the clamping cams against the bias of spring 1 1. This movement will be further improved by provision of a roller 22 interposed at the point of contact between flank 21 of the cams and bottom 2 of the casing, which converts the sliding friction of the cam to a rolling friction. The flank 23 may be made of, or coated with, an anti-friction material.

It will be noted that, when the fulcrum 15 is in its raised position, i.e. when the clamping cam recess is disengaged from pin 17, the angle defined between the obliquely extending rod 6 and the fulcrum 15 is more obtuse than that obtaining when the cam is in its clamping position, as shown in FIG. 2. As a consequence of this, the effort required to reach the clamping position is much less than that required for releasing the boot from the ski.

The fastening device for the heel clamping portion of the binding is shown in FIG. 4 which illustrates one of a pair of like fasteners mounted on the ski 33 laterally adjacent the clamping cams of the binding. As shown, each fastener comprises a bracket 32 fixed to the ski and a carrier plate 30 is pivotally mounted on bracket 32 for pivotal movement about a transverse and horizontal pivot pin 31 interconnecting the bracket an carrier plate. The transverse and horizontal pin 17 projects inwardly from the carrier plate for engagement with the clamping cam recess 16, as hereinabove described. The pin carrier plate 30 is pivotally connected at 34 to an operating pressure lever 35, the fulcrum 31 for the carrier plate being intermediate the pin 17 and the pivot 34. Thus, when the operating lever 35 is swung upwardly about pivot 34, carrier plate 30 will also swing upwardly about fulcrum 31, moving the pin 17 upwardly out of engagement with clamping cam recess 16. Thus, the heel of the boot will be disengaged from the ski. When the operating lever 35 is swung downwardly into the position shown in FIG. 4, the carrier plate 30 and its pin 17 will be correspondingly lowered about fulcrum 31 so that the pin will engage the clamping cam recess and the heel of the boot will be bound to the ski.

In order to obtain a wholly automatic safety ski binding, whose release is responsive not only to twisting moments about a horizontal axis but also to twisting moments about a vertical axis, a readily releasable fore clamp portion is mounted within a recess in the tip of the ski boot sole, similarly to the mounting of the heel clamp portion in the heel of the boot. The fore clamp portion is illustrated in FIGS. 6 to 10 to which reference will now be made.

The casing 40 for the fore clamp mechanism is of U- shaped configuration to correspond generally to the U- shaped tip of the boot sole and its open front end is partially blocked by a gate member 41 which has a central orifice 42. A sliding block 45 is.slidingly guided for reciprocating motion in casing 40, this block having a projecting shelf 45' extending outwardly through the central orifice 42 of gate 41. The opposite end of the casing is closed by wall 46 and the sliding block is biased towards the gate by a spring means which is illustrated as a pair of compression springs 47, 47 mounted between the sliding block 45 and a prismatic shoulder 48. The shoulder 48 is rotatably joumaled in the side walls of casing 40 about an eccentric shaft 48'. Rotation of the shaft 48' will adjust the bias of springs 47 so as to pre-set the desired clamping force of the device to a desired value.

The sliding block shelf 45 has a pair of forwardly extending lugs 43, 43 defining therebetween a preferably rectangular recess 49. This clamping recess is designed to cooperate with a complementary clamping member 50 mounted on pin 44 which is freely rotatably mounted on ski 33 about a vertical axis. While one end' of the clamping member is of rectangular cross section to fit the rectangular recess 49 for clamping engagement therewith, the opposite end of the clamping member 50 has inclined side walls, as shown in FIG. 10, to permit a angular shifting between the pin 44 and the lugs 43 when this side of the clamping member faces the recess 49.

Under normal operating conditions, i.e. when the fore clamp portion of the ski binding is operative to attach the tip of the boot to the ski, the springs 47 urge the sliding block 45 forwardly to hold the clamping member 50 engaged in recess 49. Rotation of the pin 44 is thus prevented unless the pre-set force of springs 47 is exceeded by the force of a twisting moment about a vertical axis. In this case, the pin rotates about its vertical axis, forcing the sliding block 45 backwards against the bias of springs 47 and thus releasing the boot tip from the ski.

It will be noted that, while the sliding block 45 is moved backwards in the released position, the clamping member 50 will still engage the gate member 41 so that a vertical shifting of the boot tip in respect of the ski is prevented, only lateral shifting having been made possible in response to the twisting moment.

While one specific embodiment of the present invention has been described and illustrated, it will be understood that many modifications and variations will occur to those skilled in the art, particularly after benefiting from this teaching, withou departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. A safety ski binding normally holding a ski boot on a ski, the ski boot having a sole tip and a heel, the ski binding comprising 1. a fore clamp portion designed to release the tip of the from the ski in response to a twisting moment about a vertical axis for permitting lateral motion between the boot tip and the ski, the fore clamp portion including a. a casing having an open front end and fitted into a conformingly shaped recess in the tip of the boot sole,

b. a sliding block slidingly guided in the casing for reciprocating motion,

c. resilient biasing means urging the sliding block forwardly through the open front end of the casmg,

d. means for pre-setting the force of the resilient bias of the biasing means, the fore clamp portion efiectuating the release when the force of the twisting moment exceeds the pre-set force of the resilient bias, and

e. a clamping member mounted on the ski for clamping engagement with the sliding block; and

. a heel clamp portion designed to release the heel of the boot from the ski in response to a twisting moment about a transverse horizontal axis for permitting release of the boot heel from the ski, the

heel clamp portion including a. a casing fitted into a conformingly shaped recess in the heel, i

b. a pin joumaled in the heel clamp portion casing at one end thereof for free rotation about a transversely extending horizontal axis, the pin being arranged near the top of the casing and having a substantially diametrical guide bore intermediate its ends,

c. an obliquely inclined rod having one end received in the guide bore for sliding movement therein, the rod extending in a direction perpendicular to the axis of the pin,

d. at least one clamping cam having a base end pivotally connected to the opposite end of the rod for pivotal movement about a transverse and horizontal fulcrum, and the opposite or clamp ing end of each clamping cam having a recess,

e. a resilient biasing means urging the sliding rod downwardly against the clamping cam and out of the guide bore,

f. means for pre-setting the force of the resilient bias of the sliding rod biasing means, the heel clamp portion effectuating the release when the force of the twisting moment about the horizontal axis exceeds the pre-set force of the resilient bias, and

g. a pin associated with each clamping cam, each pin being mounted on the ski for clamping engagement with the recess of the associated clamping cam.

2. The safety ski binding of claim 1, wherein the clamping member is mounted on the ski for free rotation about a vertical axis and has a clamping element having a side shaped complementary to a recess in the sliding block for said clamping engagement.

3. The safety ski binding of claim 2, wherein the complementary clamping element side and recess have a polygonal circumference, and an opposite side of the clamping member is inwardly tapered in respect of the recess for permitting the clamping member to be freely rotated in respect of the recess when the twisting moment exceeds the pre-set force of the resilient bias on the sliding block and thus urges the sliding block backwardly to disengage the recess of the sliding block from the clamping member.

4. The safety ski binding of claim 3, wherein the clamping member is so arranged on the ski that the polygonal clamping element side thereof extends into the open front end of the fore clamping portion casing whereby it holds the boot on the ski against vertical movement even when the sliding block is retracted from engagement therewith.

5. The safety ski binding of claim 1, wherein the means for pre-setting the force of the resilient bias of the biasing means of the sliding block comprises a prismatic shoulder to which one end of the biasing means is anchored, and an eccentric shaft mounting the prismatic shoulder in the fore clamp portion casing for rotation, rotation of the shaft causing the force of the resilient bias to be adjustably pre-set.

6. The safety ski binding of claim 1, further comprising an adjustably mounted stop means on the one end of the rod for limiting the sliding movement of the rod and preventing the rod from moving out of the guide bore.

7. The safety ski binding of claim 6, wherein the means for pre-setting the force of the resilient bias of the sliding rod biasing means comprises a threadedly mounted nut near the clamping end of the rod, said nut engaging one end of the biasing means and being accessible from outside the casing for axially moving the nut along the rod and thus to change the force of the bias.

8. The safety ski binding of claim 6, wherein each clamping cam has two differently shaped flanks respectively designed to engage the top and bottom walls of the casing. V

9. The safety ski binding of claim 8, further comprising a roller mounted on each clamping cam at the flank engaging the bottom wall of the casing whereby sliding friction is converted into rolling friction during a sliding movement of the rod.

10. The safety ski binding of claim 6, wherein a pair of symmetrically arranged ones of the clamping cams are mounted on respective sides of the sliding rod, the space between the cams being covered with a closure member to prevent access into the casing.

11. The safety ski binding of claim 1, further comprising an operating lever for moving each pin associated with each clamping cam into and out of engagement with the recess of the associated clamping cam.

12. The safety ski binding of claim 1, wherein each of said casings is mounted in the conformingly shaped recess for removal therefrom and retention therein. 

1. A safety ski binding normally holding a ski boot on a ski, the ski boot having a sole tip and a heel, the ski binding comprising
 1. a fore clamp portion designed to release the tip of the from the ski in response to a twisting moment about a vertical axis for permitting lateral motion between the boot tip and the ski, the fore clamp portion including a. a casing having an open front end and fitted into a conformingly shaped recess in the tip of the boot sole, b. a sliding block slidingly guided in the casing for reciprocating motion, c. resilient biasing means urging the sliding block forwardly through the open front end of the casing, d. means for pre-setting the force of the resilient bias of the biasing means, the fore clamp portion effectuating the release when the force of the twisting moment exceeds the pre-set force of the resilient bias, and e. a clamping member mounted on the ski for clamping engagement with the sliding block; and
 2. a heel clamp portion designed to release the heel of the boot from the ski in response to a twisting moment about a transverse horizontal axis for permitting release of the boot heel from the ski, the heel clamp portion including a. a casing fitted into a conformingly shaped recess in the heel, b. a pin journaled in the heel clamp portion casing at one end thereof for free rotation about a transversely extending horizontal axis, the pin being arranged near the top of the casing and having a substantially diametrical guide bore intermediate its ends, c. an obliquely inclined rod having one end received in the guide bore for sliding movement therein, the rod extending in a direction perpendicular to the axis of the pin, d. at least one clamping cam having a base end pivotally connected to the opposite end of the rod for pivotal movement about a transverse and horizontal fulcrum, and the opposite or clamping end of each clamping cam having a recess, e. a resilient biasing means urging the sliding rod downwardly against the clamping cam and out of the guide bore, f. means for pre-setting the force of the resilient bias of the sliding rod biasing means, the heel clamp portion effectuating the release when the force of the twisting moment about the horizontal axis exceeds the pre-set force of the resilient bias, and g. a pin associated with each clamping cam, each pin being mounted on the ski for clamping engagement with the recess of the associated clamping cam.
 2. The safety ski binding of claim 1, wherein the clamping member is mounted on the ski for free rotation about a vertical axis and has a clamping element having a side shaped complementary to a recess in the sliding block for said clamping engagement.
 2. a heel clamp portion designed to release the heel of the boot from the ski in response to a twisting moment about a transverse horizontal axis for permitting release of the boot heel from the ski, the heel clamp portion including a. a casing fitted into a conformingly shaped recess in the heel, b. a pin journaled in the heel clamp portion casing at one end thereof for free rotation about a transversely extending horizontal axis, the pin being arranged near the top of the casing and having a substantially diametrical guide bore intermediate its ends, c. an obliquely inclined rod having one end received in the guide bore for sliding movement therein, the rod extending in a direction perpendicular to the axis of the pin, d. at least one clamping cam having a base end pivotally connected to the opposite end of the rod for pivotal movement about a transverse and horizontal fulcrum, and the opposite or clamping end of each clamping cam having a recess, e. a resilient biasing means urging the sliding rod downwardly against the clamping cam and out of the guide bore, f. means for pre-setting the force of the resilient bias of the sliding rod biasing means, the heel clamp portion effectuating the release when the force of the twisting moment about the horizontal axis exceeds the pre-set force of the resilient bias, and g. a pin associated with each clamping cam, each pin being mounted on the ski for clamping engagement with the recess of the associated clamping cam.
 3. The saFety ski binding of claim 2, wherein the complementary clamping element side and recess have a polygonal circumference, and an opposite side of the clamping member is inwardly tapered in respect of the recess for permitting the clamping member to be freely rotated in respect of the recess when the twisting moment exceeds the pre-set force of the resilient bias on the sliding block and thus urges the sliding block backwardly to disengage the recess of the sliding block from the clamping member.
 4. The safety ski binding of claim 3, wherein the clamping member is so arranged on the ski that the polygonal clamping element side thereof extends into the open front end of the fore clamping portion casing whereby it holds the boot on the ski against vertical movement even when the sliding block is retracted from engagement therewith.
 5. The safety ski binding of claim 1, wherein the means for pre-setting the force of the resilient bias of the biasing means of the sliding block comprises a prismatic shoulder to which one end of the biasing means is anchored, and an eccentric shaft mounting the prismatic shoulder in the fore clamp portion casing for rotation, rotation of the shaft causing the force of the resilient bias to be adjustably pre-set.
 6. The safety ski binding of claim 1, further comprising an adjustably mounted stop means on the one end of the rod for limiting the sliding movement of the rod and preventing the rod from moving out of the guide bore.
 7. The safety ski binding of claim 6, wherein the means for pre-setting the force of the resilient bias of the sliding rod biasing means comprises a threadedly mounted nut near the clamping end of the rod, said nut engaging one end of the biasing means and being accessible from outside the casing for axially moving the nut along the rod and thus to change the force of the bias.
 8. The safety ski binding of claim 6, wherein each clamping cam has two differently shaped flanks respectively designed to engage the top and bottom walls of the casing.
 9. The safety ski binding of claim 8, further comprising a roller mounted on each clamping cam at the flank engaging the bottom wall of the casing whereby sliding friction is converted into rolling friction during a sliding movement of the rod.
 10. The safety ski binding of claim 6, wherein a pair of symmetrically arranged ones of the clamping cams are mounted on respective sides of the sliding rod, the space between the cams being covered with a closure member to prevent access into the casing.
 11. The safety ski binding of claim 1, further comprising an operating lever for moving each pin associated with each clamping cam into and out of engagement with the recess of the associated clamping cam.
 12. The safety ski binding of claim 1, wherein each of said casings is mounted in the conformingly shaped recess for removal therefrom and retention therein. 